This invention relates to pyridines substituted at the 4-position with a thioether and hydroxy containing sidechain, the corresponding methyl ether and carboxylic acid ester derivatives thereof, and the acid addition salts of said alcohols, methyl ethers and esters.
A number of compounds have been known in the art to possess immunoregulatory activity, and thus have been proposed for use in the treatment of rheumatoid arthritis and related conditions where regulation of the immune response is desired. For example, such conditions have been treated by administration of an immunoregulatory agent such as levamisole, as described in Arthritis and Rheumatism, 20, 1445 (1977) and Lancet, 1, 393 (1976). In efforts to find new and improved therapeutic agents for the treatment of these conditions, it has now been found that the novel pyridines and pyrimidines of the present invention are active as regulants of the immune response in mammals, and are thus of particular value in the treatment of rheumatoid arthritis and other conditions where regulation of the immune response is desired.
The compounds of the present invention are novel. Isomeric 3-(2-hydroxyethylthiomethyl)pyridine has been reported in the literature [Vejdelek et al., Chem. Listy. 47, 49 (1953); see Chem. Abstr. 49, 336f (1955)]; as has homologous 4-[2-(2-hydroxyethylthio)ethyl]pyridine (Cavallito, U.S. Pat. No. 3,409,626); no pharmacological activity, however, is reported for these compounds. Isomeric 2-(3-hydroxypropyl)thiomethyl)pyridine and the corresponding methyl ether derivative have also been reported (British Patent Specification No. 1,213,049); the latter compounds are claimed to be useful for treating inflammation in non-human animals, but are devoid of the desirable immunoregulatory activity of the present compounds.